Computational and Information Sciences Directorate Research Areas

Atmospheric, Biological, Organic, & Chemical Aerosols

Advisor: Y. Pan (yongle.pan.civ@mail.mil)
Adelphi, Maryland

Key words: Biological and chemical aerosol; Detection; Characterization; Raman spectroscopy; Fluorescence spectroscopy; Elastic scattering; Optical trapping; Microfluidics; Biochemical methods;

Opportunities exist to research and develop optically-based real-time atmospheric, biological, organic, and chemical aerosol detection and characterization systems. The emphasis is on measurements of individual airborne particles. In some of the options, biological or chemical aerosol particles will be classified by combining signatures from two or more optical measurements (e.g., ultraviolet laser-induced fluorescence [UV-LIF], elastic scattering pattern, and Raman spectra). In other options, particles selected according to UV-LIF spectra will be collected into a microfluidic flow cytometer, where biochemical assays may be used as a second discriminating stage after the initial screening by UV-LIF spectroscopy and elastic scattering in the first stage.

Available instrumentation includes Q-switched ns, on-demand triggerable, Ti:Sapphire laser with 2rd, 3rd, and 4th harmonic generations (200 nm-450 nm, 690 nm-1100 nm); CW Argon ion laser (514.5 nm, 495 nm, 488 nm, 476.5 nm) and intra-cavity frequency doubling (244 nm); several pulsed DPSS lasers with the fundamental, 2nd, 3rd, and 4th HG of the Nd:YLF, and Nd:YAG outputs; CCD, ICCD, EMCCD, and IR focal plane array detectors; various aerosol generation equipments; optical and electrodynamic particle levitation apparatus; a number of commercial aerosol counters and samplers; several different resolution spectrographs; and various analog and digital signal controlling, acquiring, processing, and recording systems.

References
Pan YL, et al: Environmental Science & Technology 43(2): 429, 2009
Chang RK, Pan YL: Faraday Discussions 137: 9, 2008